--- There is ________dark stain(污渍) on my coat. Who left it?
---- It’s me, Dad. I did it just for ______ fun.
| A．a ; the | B．a; / |
| C．the; the | D．the; / |
After the long journey, the Smiths returned home, ____.
| A．safe but tired | B．safely but tired |
| C．safe and tiring | D．safely and tiring |
Not everyone has realized what_______ important part the balance of________ nature plays in their life.
| A．an；the | B．/；the | C．an；/ | D．the；/ |
It’s easier to catch a _____ lion than the one that’s awake.
| A．sleep | B．slept | C．sleeping | D．to sleep |
Mr. Smith didn’t go to the party because he had a lot of experiments _____.
| A．do | B．did | C．done | D．to do |
Only if he gets a job ______ have enough money to build his own house.
| A．he can | B．can he | C．he will | D．did he |